ANALISIS VARIASI JUMLAH LAYER HARDFACING OVERLAY PADA MATERIAL A572 GR 50 DENGAN PENGELASAN FCAW TERHADAP NILAI KEKERASAN DAN METALOGRAFI

Abstract

The bulldozer blade, consisting of the cutting edge and mold board, functions primarily to push and move materials. The cutting edge, however, often experiences significant wear due to friction, which can lead to increased repair costs. To address this issue, hardfacing overlay is applied to enhance wear resistance and reduce maintenance expenses. This study aims to improve the hardness, abrasion resistance, and impact resistance of bulldozer blades made from A572 Grade 50 material by applying a hardfacing overlay using the Flux-Cored Arc Welding (FCAW) method. This method is selected to tackle the problems of soft and rust-prone surfaces on the blade. Experiments were conducted with varying numbers of hardfacing layers to optimize the process parameters. Testing involved visual inspection, liquid penetrant testing, microstructure analysis, and hardness testing. The analysis revealed that the base metal contains ferrite and pearlite phases, while the buffer layer shows a combination of austenite and vermicular ferrite phases, with the vermicular ferrite widening in buffer layer 2. The hardfacing layer contains ferrite and austenite phases, with ferrite thickness increasing as the number of hardfacing layers rises. Hardness testing showed that the combination of 2 buffer layers and 3 hardfacing layers resulted in the highest hardness, reaching 655.20 kgf/mm².